The semiconductor industry has experienced rapid growth due to improvements in the integration density of a variety of electronic components (e.g., transistors, diodes, resistors, capacitors, etc.). For the most part, this improvement in integration density has come from shrinking the semiconductor process node (e.g., shrinking the process node towards the sub-20 nm node).
Shrinking the semiconductor process node entails reductions in operating voltage and current consumption of electronic circuits developed in the semiconductor process node. For example, operating voltages have dropped from 5V to 3.3V, 2.5V, 1.8V, and even 0.9V. A wave of mobile device popularity has increased pressure in the industry to develop low power circuits that only drain minimal operating current from batteries that power the mobile devices. Lower operating current extends battery life of battery-operated mobile devices, such as smartphones, tablet computers, ultrabooks, and the like.
Leakage current is an electrical phenomenon that has become increasingly present in designs in deep sub-micron semiconductor process nodes. Leakage current occurs when a transistor is turned on even while performing no function. For example, a transistor that remains on after powering down a circuit the transistor belongs to will induce leakage current. In a power-limited environment, such as a wearable device with a very small battery, lower leakage current translates to longer battery life before needing a recharge.